Finished Reviews

SushiSwap PQ Review

Score: 53%

Overview

This is a SushiSwap Process Quality Review completed on 26 April2021. It was performed using the Process Review process (version 0.7) and is documented here. The previous review using our older process is here. The review was performed by Rex of DeFiSafety. Check out our Telegram.

The final score of the review is 53%, a fail. The breakdown of the scoring is in Scoring Appendix. For our purposes, a pass is 70%.

Summary of the Process

Very simply, the review looks for the following declarations from the developer's site. With these declarations, it is reasonable to trust the smart contracts.

  • Here are my smart contracts on the blockchain

  • Here is the documentation that explains what my smart contracts do

  • Here are the tests I ran to verify my smart contract

  • Here are the audit(s) performed on my code by third party experts

  • Here are the admin controls and strategies

Disclaimer

This report is for informational purposes only and does not constitute investment advice of any kind, nor does it constitute an offer to provide investment advisory or other services. Nothing in this report shall be considered a solicitation or offer to buy or sell any security, token, future, option or other financial instrument or to offer or provide any investment advice or service to any person in any jurisdiction. Nothing contained in this report constitutes investment advice or offers any opinion with respect to the suitability of any security, and the views expressed in this report should not be taken as advice to buy, sell or hold any security. The information in this report should not be relied upon for the purpose of investing. In preparing the information contained in this report, we have not taken into account the investment needs, objectives and financial circumstances of any particular investor. This information has no regard to the specific investment objectives, financial situation and particular needs of any specific recipient of this information and investments discussed may not be suitable for all investors.

Any views expressed in this report by us were prepared based upon the information available to us at the time such views were written. The views expressed within this report are limited to DeFiSafety and the author and do not reflect those of any additional or third party and are strictly based upon DeFiSafety, its authors, interpretations and evaluation of relevant data. Changed or additional information could cause such views to change. All information is subject to possible correction. Information may quickly become unreliable for various reasons, including changes in market conditions or economic circumstances.

This completed report is copyright (c) DeFiSafety 2021. Permission is given to copy in whole, retaining this copyright label.

Chain

This section indicates the blockchain used by this protocol.

Chain: Ethereum

Code and Team

This section looks at the code deployed on the Mainnet that gets reviewed and its corresponding software repository. The document explaining these questions is here. This review will answer the questions;

1) Are the executing code addresses readily available? (%) 2) Is the code actively being used? (%) 3) Is there a public software repository? (Y/N) 4) Is there a development history visible? (%) 5) Is the team public (not anonymous)? (Y/N)

1) Are the executing code addresses readily available? (%)

Answer: 100%

3 clicks: Docs, Dev Docs and Contracts (simple enough)

Guidance: 100% Clearly labelled and on website, docs or repo, quick to find 70% Clearly labelled and on website, docs or repo but takes a bit of looking 40% Addresses in mainnet.json, in discord or sub graph, etc 20% Address found but labelling not clear or easy to find 0% Executing addresses could not be found

They are available at website https://dev.sushi.com/sushiswap/contracts as indicated in the Appendix.

2) Is the code actively being used? (%)

Answer: 100%

Activity is well over 100 transactions a day on contract SushiBar, as indicated in the Appendix.

Percentage Score Guidance

100% More than 10 transactions a day 70% More than 10 transactions a week 40% More than 10 transactions a month 10% Less than 10 transactions a month 0% No activity

3) Is there a public software repository? (Y/N)

Answer: Yes

GitHub: https://github.com/sushiswap/sushiswap​

Is there a public software repository with the code at a minimum, but normally test and scripts also (Y/N). Even if the repo was created just to hold the files and has just 1 transaction, it gets a Yes. For teams with private repos, this answer is No.

​

4) Is there a development history visible? (%)

Answer: 100%

With 202 commits and 12 branches, this is a healthy repo.

This checks if the software repository demonstrates a strong steady history. This is normally demonstrated by commits, branches and releases in a software repository. A healthy history demonstrates a history of more than a month (at a minimum).

Guidance: 100% Any one of 100+ commits, 10+branches 70% Any one of 70+ commits, 7+branches 50% Any one of 50+ commits, 5+branches 30% Any one of 30+ commits, 3+branches 0% Less than 2 branches or less than 10 commits

How to improve this score

Continue to test and perform other verification activities after deployment, including routine maintenance updating to new releases of testing and deployment tools. A public development history indicates clearly to the public the level of continued investment and activity by the developers on the application. This gives a level of security and faith in the application.

5) Is the team public (not anonymous)? (Y/N)

Answer: Yes

SushiSwap has a team page! Sure 0xMaki is still anon, but his CTO and others in his team are not.

For a yes in this question the real names of some team members must be public on the website or other documentation. If the team is anonymous and then this question is a No.

Documentation

This section looks at the software documentation. The document explaining these questions is here.

Required questions are;

6) Is there a whitepaper? (Y/N) 7) Are the basic software functions documented? (Y/N) 8) Does the software function documentation fully (100%) cover the deployed contracts? (%) 9) Are there sufficiently detailed comments for all functions within the deployed contract code (%) 10) Is it possible to trace from software documentation to the implementation in code (%)

6) Is there a whitepaper? (Y/N)

Answer: Yes

Location: https://medium.com/sushiswap-org/grand-opening-of-sushiswap-2f04da0cd587​

How to improve this score

Ensure the white paper is available for download from your website or at least the software repository. Ideally update the whitepaper to meet the capabilities of your present application.

7) Are the basic software functions documented? (Y/N)

Answer: Yes

Location: https://dev.sushi.com/​

There is a dev section of the docs now.

How to improve this score

Write the document based on the deployed code. For guidance, refer to the SecurEth System Description Document.

8) Does the software function documentation fully (100%) cover the deployed contracts? (%)

Answer: 40%

The dev section of the docs is a work in progress. Only 1 contract is documented; LendingPair. The Oracle section has good documentation

Guidance:

100% All contracts and functions documented 80% Only the major functions documented 79-1% Estimate of the level of software documentation 0% No software documentation

How to improve this score

This score can improve by adding content to the requirements document such that it comprehensively covers the requirements. For guidance, refer to the SecurEth System Description Document . Using tools that aid traceability detection will help.

9) Are there sufficiently detailed comments for all functions within the deployed contract code (%)

Answer: 45

There is a CtC of 31%. The comments are good but without NatSpec.

Code examples are in the Appendix. As per the SLOC, there is 31% commenting to code (CtC).

The Comments to Code (CtC) ratio is the primary metric for this score.

Guidance: 100% CtC > 100 Useful comments consistently on all code 90-70% CtC > 70 Useful comment on most code 60-20% CtC > 20 Some useful commenting 0% CtC < 20 No useful commenting

How to improve this score

This score can improve by adding comments to the deployed code such that it comprehensively covers the code. For guidance, refer to the SecurEth Software Requirements.

10) Is it possible to trace from software documentation to the implementation in code (%)

Answer: 0%

There is not enough documentation for traceability.

Guidance: 100% - Clear explicit traceability between code and documentation at a requirement level for all code 60% - Clear association between code and documents via non explicit traceability 40% - Documentation lists all the functions and describes their functions 0% - No connection between documentation and code

How to improve this score

This score can improve by adding traceability from requirements to code such that it is clear where each requirement is coded. For reference, check the SecurEth guidelines on traceability.

Testing

This section looks at the software testing available. It is explained in this document. This section answers the following questions;

11) Full test suite (Covers all the deployed code) (%) 12) Code coverage (Covers all the deployed lines of code, or explains misses) (%) 13) Scripts and instructions to run the tests (Y/N) 14) Report of the results (%) 15) Formal Verification test done (%) 16) Stress Testing environment (%)

11) Is there a Full test suite? (%)

Answer: 80%

The Test to Code is 104%, which puts an

This score is guided by the Test to Code ratio (TtC). Generally a good test to code ratio is over 100%. However the reviewers best judgement is the final deciding factor.

Guidance: 100% TtC > 120% Both unit and system test visible 80% TtC > 80% Both unit and system test visible 40% TtC < 80% Some tests visible 0% No tests obvious

How to improve this score

This score can improve by adding tests to fully cover the code. Document what is covered by traceability or test results in the software repository.

12) Code coverage (Covers all the deployed lines of code, or explains misses) (%)

Answer: 50%

No indication of code coverage.

Guidance: 100% - Documented full coverage 99-51% - Value of test coverage from documented results 50% - No indication of code coverage but clearly there is a reasonably complete set of tests 30% - Some tests evident but not complete 0% - No test for coverage seen

How to improve this score

This score can improve by adding tests achieving full code coverage. A clear report and scripts in the software repository will guarantee a high score.

13) Scripts and instructions to run the tests (Y/N)

Answer: Yes

Instructions found at https://github.com/sushiswap/sushiswap/blob/master/docs/DEVELOPMENT.md​

How to improve this score

Add the scripts to the repository and ensure they work. Ask an outsider to create the environment and run the tests. Improve the scripts and docs based on their feedback.

14) Report of the results (%)

Answer: 0%

No report found.

Guidance: 100% - Detailed test report as described below 70% - GitHub Code coverage report visible 0% - No test report evident

How to improve this score

Add a report with the results. The test scripts should generate the report or elements of it.

15) Formal Verification test done (%)

Answer: 60%

There is evidence of formal verification specs in https://github.com/sushiswap/sushiswap/tree/master/spec but no evidence of thest being run.

16) Stress Testing environment (%)

Answer: 0%

No evidence of a test network.

Security

This section looks at the 3rd party software audits done. It is explained in this document. This section answers the following questions;

17) Did 3rd Party audits take place? (%) 18) Is the bounty value acceptably high?

17) Did 3rd Party audits take place? (%)

Answer: 20%

No evidence of audit reports on their website, docs or developer docs. Their security sections only talk about bug bounties.. This appears intentional. Therefore score of 20% indicating no audits, even though for the previous audit we wrote the text below;

Written Sept 2020 - Two audits were performed after deployment from Quantstamp and PeckShield. Some changes were implemented while others will be dealt with by the team without contract modification as the contracts are in heavy use. No critical flaws found. Score as per below 70

Guidance:

  1. Multiple Audits performed before deployment and results public and implemented or not required (100%)

  2. Single audit performed before deployment and results public and implemented or not required (90%)

  3. Audit(s) performed after deployment and no changes required. Audit report is public. (70%)

  4. No audit performed (20%)

  5. Audit Performed after deployment, existence is public, report is not public and no improvements deployed OR smart contract address' not found, question 1 (0%)

18) Is the bounty value acceptably high (%)

Answer: 75%

There is no indication of a bug bounty (or audits) on their docs or website. Yet when I googled, the Immunifi page popped up. The bounty is US$1M but I will take off 25% as it is not clearly indicated.

Bug Bounty Location: https://immunefi.com/bounty/sushiswap/​

Guidance:

100% Bounty is 10% TVL or at least 1M 90% Bounty is 5% TVL or at least 500k 70% Bounty is 100k or over 40% Bounty is 50k or over 20% Bug bounty program bounty is less than 50k 0% No bug bounty program offered

Access Controls

This section covers the documentation of special access controls for a DeFi protocol. The admin access controls are the contracts that allow updating contracts or coefficients in the protocol. Since these contracts can allow the protocol admins to "change the rules", complete disclosure of capabilities is vital for user's transparency. It is explained in this document. The questions this section asks are as follow;

19) Can a user clearly and quickly find the status of the admin controls? 20) Is the information clear and complete? 2`) Is the information in non-technical terms that pertain to the investments? 22) Is there Pause Control documentation including records of tests?

19) Can a user clearly and quickly find the status of the admin controls (%)

Answer: 100%

Looked at Governance after Docs

Location: https://docs.sushi.com/governance/current-governance-mdoel​

Guidance: 100% Clearly labelled and on website, docs or repo, quick to find 70% Clearly labelled and on website, docs or repo but takes a bit of looking 40% Access control docs in multiple places and not well labelled 20% Access control docs in multiple places and not labelled 0% Admin Control information could not be found

20) Is the information clear and complete (%)

Answer: 55%

The Governance models description mentions the capabilities of the multi-sigs, their signers and the long term governance roles.

a) The number of the updates are only very generally given (such as "Major Structural Changes") so we might imply major changes therefore score 15%

b) The addresses of the multisigs are not given, but the type clearly is so 25%

c) The capabilities are not described well except for (indications such as "Major Structural Changes") so we might imply major changes and a vague indication of operational changes so score 15%

Guidance: All the contracts are immutable -- 100% OR a) All contracts are clearly indicated as upgradeable (or not) -- 30% AND b) The type of ownership is clearly indicated (OnlyOwner / MultiSig / Defined Roles) -- 30% AND c) The capabilities for change in the contracts are described -- 30%

How to improve this score

Create a document that covers the items described above. An example is enclosed.

21) Is the information in non-technical terms that pertain to the investments (%)

Answer: 70%

The description is in non-technical language but it is not clear how much impact changes to the contracts or constants could have on the investments.

Guidance: 100% All the contracts are immutable 90% Description relates to investments safety and updates in clear, complete non-software language

50% Description is in clear, complete non-software language but does not relate to the investments 30% Description all in software specific language 0% No admin control information could not be found

How to improve this score

Create a document that covers the items described above in plain language that investors can understand. An example is enclosed.

22) Is there Pause Control documentation including records of tests (%)

Answer: 0%

There is no discussion of a pause control.

Guidance: 100% All the contracts are immutable or no pause control needed and this is explained OR 100% Pause control(s) are clearly documented and there is records of at least one test within 3 months 80% Pause control(s) explained clearly but no evidence of regular tests 40% Pause controls mentioned with no detail on capability or tests 0% Pause control not documented or explained

How to improve this score

Create a document that covers the items described above in plain language that investors can understand. An example is enclosed.

Appendices

Author Details

The author of this review is Rex of DeFi Safety.

Email : [email protected] Twitter : @defisafety

I started with Ethereum just before the DAO and that was a wonderful education. It showed the importance of code quality. The second Parity hack also showed the importance of good process. Here my aviation background offers some value. Aerospace knows how to make reliable code using quality processes.

I was coaxed to go to EthDenver 2018 and there I started SecuEth.org with Bryant and Roman. We created guidelines on good processes for blockchain code development. We got EthFoundation funding to assist in their development.

Process Quality Reviews are an extension of the SecurEth guidelines that will further increase the quality processes in Solidity and Vyper development.

DeFiSafety is my full time gig and we are working on funding vehicles for a permanent staff.

Scoring Appendix

Executing Code Appendix

Code Used Appendix

Example Code Appendix

pragma solidity 0.6.12;
​
​
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
import "@openzeppelin/contracts/utils/EnumerableSet.sol";
import "@openzeppelin/contracts/math/SafeMath.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "./SushiToken.sol";
​
​
interface IMigratorChef {
// Perform LP token migration from legacy UniswapV2 to SushiSwap.
// Take the current LP token address and return the new LP token address.
// Migrator should have full access to the caller's LP token.
// Return the new LP token address.
//
// XXX Migrator must have allowance access to UniswapV2 LP tokens.
// SushiSwap must mint EXACTLY the same amount of SushiSwap LP tokens or
// else something bad will happen. Traditional UniswapV2 does not
// do that so be careful!
function migrate(IERC20 token) external returns (IERC20);
}
​
// MasterChef is the master of Sushi. He can make Sushi and he is a fair guy.
//
// Note that it's ownable and the owner wields tremendous power. The ownership
// will be transferred to a governance smart contract once SUSHI is sufficiently
// distributed and the community can show to govern itself.
//
// Have fun reading it. Hopefully it's bug-free. God bless.
contract MasterChef is Ownable {
using SafeMath for uint256;
using SafeERC20 for IERC20;
​
// Info of each user.
struct UserInfo {
uint256 amount; // How many LP tokens the user has provided.
uint256 rewardDebt; // Reward debt. See explanation below.
//
// We do some fancy math here. Basically, any point in time, the amount of SUSHIs
// entitled to a user but is pending to be distributed is:
//
// pending reward = (user.amount * pool.accSushiPerShare) - user.rewardDebt
//
// Whenever a user deposits or withdraws LP tokens to a pool. Here's what happens:
// 1. The pool's `accSushiPerShare` (and `lastRewardBlock`) gets updated.
// 2. User receives the pending reward sent to his/her address.
// 3. User's `amount` gets updated.
// 4. User's `rewardDebt` gets updated.
}
​
// Info of each pool.
struct PoolInfo {
IERC20 lpToken; // Address of LP token contract.
uint256 allocPoint; // How many allocation points assigned to this pool. SUSHIs to distribute per block.
uint256 lastRewardBlock; // Last block number that SUSHIs distribution occurs.
uint256 accSushiPerShare; // Accumulated SUSHIs per share, times 1e12. See below.
}
​
// The SUSHI TOKEN!
SushiToken public sushi;
// Dev address.
address public devaddr;
// Block number when bonus SUSHI period ends.
uint256 public bonusEndBlock;
// SUSHI tokens created per block.
uint256 public sushiPerBlock;
// Bonus muliplier for early sushi makers.
uint256 public constant BONUS_MULTIPLIER = 10;
// The migrator contract. It has a lot of power. Can only be set through governance (owner).
IMigratorChef public migrator;
​
// Info of each pool.
PoolInfo[] public poolInfo;
// Info of each user that stakes LP tokens.
mapping (uint256 => mapping (address => UserInfo)) public userInfo;
// Total allocation poitns. Must be the sum of all allocation points in all pools.
uint256 public totalAllocPoint = 0;
// The block number when SUSHI mining starts.
uint256 public startBlock;
​
event Deposit(address indexed user, uint256 indexed pid, uint256 amount);
event Withdraw(address indexed user, uint256 indexed pid, uint256 amount);
event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount);
​
constructor(
SushiToken _sushi,
address _devaddr,
uint256 _sushiPerBlock,
uint256 _startBlock,
uint256 _bonusEndBlock
) public {
sushi = _sushi;
devaddr = _devaddr;
sushiPerBlock = _sushiPerBlock;
bonusEndBlock = _bonusEndBlock;
startBlock = _startBlock;
}
​
function poolLength() external view returns (uint256) {
return poolInfo.length;
}
​
// Add a new lp to the pool. Can only be called by the owner.
// XXX DO NOT add the same LP token more than once. Rewards will be messed up if you do.
function add(uint256 _allocPoint, IERC20 _lpToken, bool _withUpdate) public onlyOwner {
if (_withUpdate) {
massUpdatePools();
}
uint256 lastRewardBlock = block.number > startBlock ? block.number : startBlock;
totalAllocPoint = totalAllocPoint.add(_allocPoint);
poolInfo.push(PoolInfo({
lpToken: _lpToken,
allocPoint: _allocPoint,
lastRewardBlock: lastRewardBlock,
accSushiPerShare: 0
}));
}

SLOC Appendix

Solidity Contracts

Language

Files

Lines

Blanks

Comments

Code

Complexity

Solidity

6

1287

134

276

877

126

Comments to Code 276 / 877 = 31%

Tests

Language

Files

Lines

Blanks

Comments

Code

Complexity

TypeScript

10

1099

149

41

909

4

Tests to Code 909 / 877 =104 %